I’ve reached the pinnacle of awkwardness.
At the end of my driving lesson my instructor and I were sitting in the car, reviewing the lesson, and he congratulated me on doing a good job. He then lifted his arm, to shake my hand, but since we were in the car he had to raise it a little higher. I saw this gesture, and went in for the high five!
It took a fraction of a second for my brain to realize what I had done, but by that point it was too late.
On the up side, it happened right at the end of the lesson, but on the down side, I still have 4 lessons left with him.